U.S. patent application number 10/745037 was filed with the patent office on 2005-04-21 for balun built in multiple ceramic layers.
Invention is credited to Wang, Hsing-Sen.
Application Number | 20050083162 10/745037 |
Document ID | / |
Family ID | 34511701 |
Filed Date | 2005-04-21 |
United States Patent
Application |
20050083162 |
Kind Code |
A1 |
Wang, Hsing-Sen |
April 21, 2005 |
Balun built in multiple ceramic layers
Abstract
A balance-to-unbalance transformer (10), comprising an input
terminal (11), a first output terminal (12), a second output
terminal (13), a first circuit line comprising at least two
capacitors (C1, C2) in parallel with each other and a first
inductor L1 in series with the capacitors (C1, C2), wherein one
electrode of each of the capacitors (C1, C2) are grounded, and a
second circuit line comprising at least two capacitors (C3, C4) in
series with each other and a second inductor (L2) in parallel with
the capacitors (C3, C4), wherein one end of the second inductor
(L2) is grounded. One end of the first circuit line and one end of
the second circuit line are connected in parallel with the input
terminal (11), and the other ends of the first and second circuit
lines are the first and second output terminal, respectively.
Inventors: |
Wang, Hsing-Sen; (Taoyuan
County, TW) |
Correspondence
Address: |
LAW OFFICES OF DAVID PAI
1001 FOURTH AVENUE, SUITE 3200
SEATTLE
WA
98154
US
|
Family ID: |
34511701 |
Appl. No.: |
10/745037 |
Filed: |
December 23, 2003 |
Current U.S.
Class: |
336/232 |
Current CPC
Class: |
H03H 2001/0085 20130101;
H01F 17/0013 20130101; H03H 7/42 20130101 |
Class at
Publication: |
336/232 |
International
Class: |
H01F 027/28 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2003 |
TW |
92129050 |
Claims
What is claimed is:
1. A balance-to-unbalance (Balun) transformer structure (10),
comprising: an input terminal (11); a first output terminal (12); a
second output terminal (13); a first circuit line, which comprises
at least two capacitors (C1, C2) in parallel with each other and a
first inductor L1 in series with the capacitors (C1, C2), wherein
one electrode of each of the capacitors (C1, C2) are grounded; and
a second circuit line, which comprises at least two capacitors (C3,
C4) in series with each other and a second inductor (L2) in
parallel with the capacitors (C3, C4), wherein one end of the
second inductor (L2) is grounded, wherein one end of the first
circuit line and one end of the second circuit line are connected
in parallel with the input terminal (11), and the other ends of the
first and second circuit lines are the first and second output
terminals, respectively.
2. The balance-to-unbalance (Balun) transformer structure as
recited in claim 1, wherein the input terminal is provided for
inputting an unbalanced signal and each of the first and second
output terminals is provided for outputting a balanced signal, and
the power of the outputted balanced signal is one half of the power
of the inputted unbalanced signal.
3. The balance-to-unbalance (Balun) transformer structure as
recited in claim 2, wherein the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength.
4. A Balun transformer built in multiple ceramic layers,
comprising: an input terminal; a first output terminal; a second
output terminal; at least four ceramic layers, wherein all the
input terminal and the first and second output terminals are
positioned on one outer surface of a laminated structure of the
ceramic layers; at least five patterned metal layers provided for a
plurality of capacitance electrodes of first to fourth capacitors;
a plurality of wiring lines provided for first and second
inductors; and a plurality of via holes provided for electrically
connecting the capacitance electrodes and the first and second
inductors located between respective metal layers, so as to
constitute the Balun transformer, wherein the first and second
capacitors in parallel with each other are series connected with
the first inductor, and one electrode of each of the first and
second capacitors are grounded, the third and fourth capacitors in
series with each other are parallel connected with the second
inductor, and one end of the second inductor is grounded, and one
end of the first capacitor and one end of the third capacitor are
connected in parallel with the input terminal, and the other end of
the second and fourth capacitors are the first and second output
terminals, respectively.
5. The Balun transformer built in multiple ceramic layers as
recited in claim 4, wherein the respective dielectric constants of
the ceramic layers are within a range of 7 to 8.
6. The Balun transformer built in multiple ceramic layers as
recited in claim 4, wherein the input terminal is provided for
inputting an unbalanced signal and each of the first and second
output terminals is provided for outputting a balanced signal, and
the power of the outputted balanced signal is one half of the power
of the inputted unbalanced signal.
7. The Balun transformer built in multiple ceramic layers as
recited in claim 6, wherein the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a balance-to-unbalance (Balun)
transformer, and, more particularly, to a Balun built in multiple
ceramic layers.
[0003] 2. Description of the Related Art
[0004] In terms of the technology of wireless network
communication, a balance-to-unbalance (Balun) transformer is a
crucial component, which is provided between a balanced circuit and
an unbalanced circuit for transforming signals.
[0005] Conventionally, the Balun transformer is composed of
microstrips or windings. However, if the conventional Balun
transformer is used in applications with a radio frequency of
several hundreds MHz or several GHz, the size of the Balun
transformer and the weight thereof will be too enormous to be
practically incorporated in such applications.
[0006] Thus, there is a need for a Balun transformer with reduced
size and weight.
BRIEF SUMMARY OF THE INVENTION
[0007] In view of the above, it is thus an object of the present
invention to provide a balance-to-unbalance (Balun) transformer
structure. According to a first preferred embodiment of the present
invention, the Balun transformer structure comprises an input
terminal, a first output terminal, a second output terminal, a
first circuit line, which comprises at least two capacitors in
parallel with each other and a first inductor in series with the
capacitors, wherein one electrode of each of the capacitors are
grounded, and a second circuit line, which comprises at least two
capacitors in series with each other and a second inductor in
parallel with the capacitors, wherein one end of the second
inductor is grounded. In more detail, one end of the first circuit
line and one end of the second circuit line are connected in
parallel with the input terminal, and the other ends of the first
and second circuit lines are the first and second output terminals,
respectively.
[0008] Preferably, the input terminal is provided for inputting an
unbalanced signal and each of the first and second output terminals
are provided for outputting a balanced signal, and the power of the
outputted balanced signal is one half of the power of the inputted
unbalanced signal according to the first preferred embodiment of
the present invention.
[0009] Preferably, the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength according to the first preferred embodiment of
the present invention.
[0010] Still, it is another object of the present invention to
provide a Balun transformer built in multiple ceramic layers.
According to a second preferred embodiment of the present
invention, the Balun transformer built in multiple ceramic layers
comprises an input terminal, a first output terminal, a second
output terminal, at least four ceramic layers, wherein all the
input terminal and the first and second output terminals are
positioned on one outer surface of a laminated structure of the
ceramic layers, at least five patterned metal layers provided for a
plurality of capacitance electrodes of first to fourth capacitors,
a plurality of wiring lines provided for first and second
inductors, and a plurality of via holes provided for electrically
connecting the capacitance electrodes and the first and second
inductors located between respective metal layers, so as to
constitute the Balun transformer, wherein the first and second
capacitors in parallel with each other are series connected with
the first inductor, one electrode of each of the first and second
capacitors are grounded, the third and fourth capacitors in series
with each other are parallel connected with the second inductor,
and one end of the second inductor is grounded. In more detail, one
end of the first capacitor and one end of the third capacitor are
connected in parallel with the input terminal, and the other ends
of the second and fourth capacitors are the first and second output
terminals, respectively.
[0011] Preferably, the respective dielectric constants of the
ceramic layers are within a range of 7 to 8 according to the second
preferred embodiment of the present invention.
[0012] Preferably, the input terminal is provided for inputting an
unbalanced signal and each of the first and second output terminals
is provided for outputting a balanced signal, and the power of the
outputted balanced signal is one half of the power of the inputted
unbalanced signal according to the second preferred embodiment of
the present invention.
[0013] Preferably, the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength according to the second preferred embodiment of
the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a circuit diagram of a Balun transformer
according to the first preferred embodiment of the present
invention.
[0015] FIGS. 2A and 2B respectively illustrate top and front
cross-sectional view of multiple ceramic layers embedded with the
Balun transformer according to the second preferred embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Please refer to FIG. 1, illustrating a circuit diagram of a
Balun transformer according to the first preferred embodiment of
the present invention.
[0017] As illustrated in FIG. 1, a Balun transformer structure 10
comprises an input terminal 11, first and second output terminals
12, 13, a first circuit line, which comprises at least two
capacitors C1, C2 in parallel with each other and a first inductor
L1 in series with the capacitors C1, C2, wherein one electrode of
each of the capacitors C1, C2 are grounded, and a second circuit
line, which comprises at least two capacitors C3, C4 in series with
each other and a second inductor L2 in parallel with the capacitors
C3, C4, wherein one end of the second inductor L2 is grounded.
Preferably, one end of the first circuit line and one end of the
second circuit line are connected in parallel with the input
terminal 11, and the other ends of the first and second circuit
lines are the first and second output terminals 12, 13,
respectively.
[0018] It is to be noted that the input terminal 11 is provided for
inputting an unbalanced signal and each of the first and second
output terminals 12, 13 is provided for outputting a balanced
signal, and, preferably, the power of the outputted balanced signal
is one half of the power of the inputted unbalanced signal
according to the first preferred embodiment of the present
invention.
[0019] It is preferred that the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength according to the first preferred embodiment of
the present invention.
[0020] For enabling a reduction in the volume of the Balun
transformer 10 according to the first preferred embodiment of the
present invention, a Balun transformer 10 built in multiple ceramic
layers are illustrated in FIGS. 2A and 2B according to the second
preferred embodiment of the present invention.
[0021] As illustrated in FIGS. 2A and 2B, the Balun transformer 10
built in multiple ceramic layers comprises an input terminal 11,
first and second output terminals 12, 13, at least four ceramic
layers 21 to 24, wherein all the input terminal 11 and the first
and second output terminals 12, 13 are positioned on one outer
surface of a laminated structure of the ceramic layers 21 to 24, at
least five patterned metal layers provided for a plurality of
capacitance electrodes 31 of first to fourth capacitors C1, C2, C3
and C4, a plurality of wiring lines 33 provided for first and
second inductors L1 and L2, and a plurality of via holes 32
provided for electrically connecting the capacitance electrodes 31
and the first and second inductors L1 and L2 located between
respective metal layers, so as to constitute the Balun transformer
10.
[0022] It is to be noted that the first and second capacitors C1
and C2 in parallel with each other are series connected with the
first inductor L1, and one electrode of each of the first and
second capacitors C1 and C2 are grounded. In addition, the third
and fourth capacitors C3 and C4 in series with each other are
parallel connected with the second inductor L2, and one end of the
second inductor L2 is grounded. In more detail, one end of the
first capacitor C1 and one end of the third capacitor C3 are
connected in parallel with the input terminal 11, and the other end
of the second and fourth capacitors C2 and C4 are the first and
second output terminals 12, 13, respectively.
[0023] It is preferred that the respective dielectric constants of
the ceramic layers 21 to 24 are within a range of 7 to 8 according
to the second preferred embodiment of the present invention.
[0024] Similar to the first preferred embodiment, the input
terminal 11 is provided for inputting an unbalanced signal and each
of the first and second output terminals 12, 13 is provided for
outputting a balanced signal, and, preferably, the power of the
outputted balanced signal is one half of the power of the inputted
unbalanced signal according to the second preferred embodiment of
the present invention.
[0025] Preferably, the unbalanced signal is a positive
quarter-wavelength and the balanced signal is a negative
quarter-wavelength according to the first preferred embodiment of
the present invention.
[0026] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it is apparent
that certain changes and modifications may be practiced within the
scope of the appended claims. Accordingly, the present embodiments
are to be considered as illustrative and not restrictive, and the
invention is not to be limited to the details given herein, but may
be modified within the scope and equivalents of the appended
claims.
* * * * *